Andrei....We too are in FL....I'll tell you this.....buy bottled.....get it from the 'wholesale stores' (BJ's, Costco etc). As for the rain collection.....I tried this very very briefly. Just for chuckles we put a 33 gallon can under the roof during our usual seasonal daily rain.....the can filled in less than 2 minutes. Plan to have you system fill quickly and need to hold a lot but also plan for these very long times between rains (and they are getting longer)......good luck.